CVE-2026-30926 HIGH

CVE-2026-30926: SiYuan Note publish service authorization bypass allows low-privilege users to modify notebook content

Vendor Siyuan-Note
Product siyuan
Weakness CWE-284
Published March 9, 2026
Last update March 10, 2026

CVSS base score

7.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

What the vulnerability does

01Description

SiYuan is a personal knowledge management system. Prior to 3.5.10, a privilege escalation vulnerability exists in the publish service of SiYuan Note that allows low-privilege publish accounts (RoleReader) to modify notebook content via the /api/block/appendHeadingChildren API endpoint. The endpoint requires only the model.CheckAuth role, which accepts RoleReader sessions, but it does not enforce stricter checks, such as CheckAdminRole or CheckReadonly. This allows remote authenticated publish users with read-only privileges to append new blocks to existing documents, compromising the integrity of stored notes.

Key dates

02Disclosure timeline

March 9, 2026 CVE published
March 10, 2026 Record updated